Springboot2.2中的RSocket体验

Springboot2.2中的RSocket体验

什么是RSocket?

RSocket是一种二进制协议，用于TCP、websocket和Aeron等字节流传输。它通过异步消息在单个连接上传递，支持以下对称交互模型:

1. request/response (stream of 1)
2. request/stream (finite stream of many)
3. fire-and-forget (no response)
4. channel (bi-directional streams)

一个发展过程

下面是一个简单的demo,包括两个模块producer和consumer供大家学习.

producer

核心pom.xml

       
            org.springframework.boot
            spring-boot-starter-rsocket
        

Repository

@Slf4j
@Component
public class MarketDataRepository {

    private static final int BOUND = 100;

    private Random random = new Random();

    public Flux getAll(String stock) {
        return Flux.fromStream(Stream.generate(() -> getMarketDataResponse(stock)))
                .log()
                .delayElements(Duration.ofSeconds(1));
    }

    public Mono getOne(String stock) {
        return Mono.just(getMarketDataResponse(stock));
    }

    public void add(MarketData marketData) {
        log.info("New market data: {}", marketData);
    }

    private MarketData getMarketDataResponse(String stock) {
        return new MarketData(stock, random.nextInt(BOUND));
    }
}

这个MarketDataRepository是一个简易模拟,当然你也可以使用R2DBC猛戳

controller

@Controller
public class MarketDataRSocketController {
    private final MarketDataRepository marketDataRepository;

    public MarketDataRSocketController(MarketDataRepository marketDataRepository) {
        this.marketDataRepository = marketDataRepository;
    }

    @MessageMapping("currentMarketData")
    public Mono currentMarketData(MarketDataRequest marketDataRequest) {
        return marketDataRepository.getOne(marketDataRequest.getStock());
    }

    @MessageMapping("feedMarketData")
    public Flux feedMarketData(MarketDataRequest marketDataRequest) {
        return marketDataRepository.getAll(marketDataRequest.getStock());
    }

    @MessageMapping("collectMarketData")
    public Mono collectMarketData(MarketData marketData) {
        marketDataRepository.add(marketData);
        return Mono.empty();
    }

    @MessageExceptionHandler
    public Mono handleException(Exception e) {
        return Mono.just(MarketData.fromException(e));
    }
}

这个Controller用来处理消费者的RSocket请求,
注意这里的@MessageMapping其实可以理解为就是@RequestMapping,其实就是提供路由.

application.properties

spring.rsocket.server.port=7000

配置,目前只有四个,可以参考这里

异常处理

@MessageExceptionHandler
public Mono handleException(Exception e) {
    return Mono.just(MarketData.fromException(e));
}

注意:不同的模式需要不同的异常处理,这里是针对请求/响应的异常处理,啦啦啦.

consumer

核心pom.xml

       
            org.springframework.boot
            spring-boot-starter-rsocket
        

配置Configuration

@Lazy
@Configuration
public class ConsumerConfiguration {

    @Bean
    RSocket rSocket() {
        return RSocketFactory
                .connect()
                .dataMimeType(MimeTypeUtils.APPLICATION_JSON_VALUE)
                .frameDecoder(PayloadDecoder.ZERO_COPY)
                //.transport(TcpClientTransport.create("47.96.70.206",7000)) 个人服务器已关闭
                .transport(TcpClientTransport.create("127.0.0.1",7000))
                .start()
                .block();
    }

    @Bean
    RSocketRequester requester(RSocketStrategies rSocketStrategies) {

        //废弃版
        //RSocketRequester.create(this.rSocket(),MimeTypeUtils.APPLICATION_JSON, rSocketStrategies);

        return  RSocketRequester.wrap(this.rSocket(),
                MimeTypeUtils.APPLICATION_JSON, rSocketStrategies);
    }
}

这里，我们创建RSocket Client(消费者)，并将其配置端口7000,使用TCP传输。注意，这是我们之前配置的服务器端口。
接下来，我们将定义一个RSocketRequester的实例，它是一个围绕RSocket的包装器。这个bean将帮助我们与RSocket服务器进行交互。
定义了这些bean配置之后，我们就有了一个基本的结构。

消费者Controller

@RestController
public class MarkDataRestController {
    private final RSocketRequester requester;

    public MarkDataRestController(RSocketRequester requester) {
        this.requester = requester;
    }

    /**
     *功能描述 Request/Response模式,目前通用的请求/响应模式
     * @author KL
     * @date 2019/5/27
     * @param stock
     * @return org.reactivestreams.Publisher
     */
    @GetMapping("/current/{stock}")
    public Publisher current(@PathVariable String stock){
        return requester
                .route("currentMarketData")
                .data(new MarketDataRequest(stock))
                .retrieveMono(MarketData.class);
    }
    /**
     *功能描述 Request/Stream模式  ,一个简单的请求返回多个响应.
     * Request/Stream模式是一个更复杂的交互模型，其中客户机发送一个请求，但是在一段时间内从服务器获得多个响应。
     * @author KL
     * @date 2019/5/27
     * @param stock
     * @return org.reactivestreams.Publisher
     */
    @GetMapping(value = "/feed/{stock}", produces = MediaType.TEXT_EVENT_STREAM_VALUE)
    public Publisher feed(@PathVariable("stock") String stock) {
        return requester.route("feedMarketData")
                .data(new MarketDataRequest(stock))
                .retrieveFlux(MarketData.class);
    }

    /**
     *功能描述 Fire And Forget模式,其实就是Client推送给Server端
     * @author KL
     * @date 2019/5/27
     * @param
     * @return org.reactivestreams.Publisher
     */
    @GetMapping(value = "/collect")
    public Publisher collect() {
        return requester.route("collectMarketData")
                .data(getMarketData())
                .send();
    }

    private MarketData getMarketData() {
        return new MarketData("X", new Random().nextInt(10));
    }
}

总结

RSocket为我们提供了一种新的服务通信思路,我们可以将RSocket应用到微服务框架中去,尝试去替代Http的方案.
现在Springboot支持了,在过不久dubbo3.0也支持了,哈哈.学习吧.